Apparatus for producing curled yarn



Feb. 18,1958 L. VANDAMME ETAL 2,323,513

APPARATUS FOR PRODUCING CURLED YARN Original Filed June 11, 1954 I 3 Sheets-Sheet 1 Z I J I J I 7 g /4 Z 4 0-' A i m ll / /l Z i INVENTORS Feb. 18, 1958 Original Filed June 11, 1954 L. VANDAMME ETAL APPARATUS FOR PRODUCING CURLED YARN 3 Sheets-Sheet 2 I i i I I m l INVENTOR Law/s V/I/VD/l/f/f A TTOEA/f v Feb. 18, 1958 L. VANDAMME ETAL 2,823,513

' APPARATUS FOR PRODUCING CURLED YARN 7 Original Filed June 11, v1954 5 Sheets-Sheet a LIA/5 INVENTORS 400/: I/A/VDA/I/VE Y 400/5 A 0 X679 United States PatentO APPARATUS FOR PRODUCING. CURLED YARN .LouisVandamme and Louis Rouyer,Sanka-France, as-

;signors .to Mouli'nage eti Rtorderie de .Chavanoz, Cliavanoz, France; a'corporation 'of FranceiOriginal =applicationlune 11,. 1954;;iS'erial No."-436,077,

This invention relates to the production .o'fj'a curled yarn'and =more-particularly"toapparatus for'setting a false twist in a continuously advancing yarn.

This application is a division of my copending application Serial No. 436,077 filed June 11, 1954, now U. S. Patent No. 2,761,272.

An object is to provide a novel and improved apparatus of the above type.

Copending application Serial No. 331,158 filed January 14, 1952, now U. S. Patent No. 2,741,893, discloses a method of producing a curl which involves passing the yarn through a false twister, allowing the false twist to travel along the yarn in a direction counter to the direction of feed, and setting the twist so produced by hot water or steam.

The present invention provides improved apparatus for setting the false twist thermally and in a dry state, i. e. without subjecting the yarn to hot water or steam. The setting is effected for example by contacting the yarn with a plate heated by the internal circulation of a hot fluid such as oil, or by subjecting the yarn to heating by a high frequency electric field, or to a bank of lights or burners emitting infra red rays.

The nature of the invention will be better understood by referring to the following description, taken in connection with the accompanying drawing in which certain specific embodiments have been set forth for purposes of illustration.

In the drawings:

Fig. 1 is a front elevation of an apparatus for setting the false twist by contacting the yarn with a heated member;

Fig. 2 is a side elevation thereof;

Fig. 3 is a side elevation of a portion of an apparatus for heating the yarn by a high frequency field; and

Fig. 4 is a side elevation of a portion of an apparatus for heating the yarn by infra red radiations.

Referring to Figs. 1 and 2 of the drawings more in detail the yarn 8 which is of the thermoplastic type and may for example constitute polyhexamethylene adipamide is unwound endwise from a bobbin 1 and is passed through a friction device 2, shown as of the grid type, although any other suitable type of friction drag may be used. From the friction device 2, the yarn passes between a feed roll 3 and a presser roll 9. The roll 3 is driven from main shaft A through bevel gears B and C and through a gear train comprising gears 4, 5, 6 and 7. The main shaft A may be driven from any suitable source of power, not shown.

From the feed rolls the yarn passes over a guide roll 10 and in contact with the outside of a hollow curved metal casing 11 and through a guide eyelet 10'. The curvature of the metal casing 11 is such that the yarn is caused to contact the casing for a substantial distance in its travel. The hollow casing is connected by ducts 11a and 11b to a heating device 12 such as a boiler containing a fiuid which is maintained at constant temperature by a thermostat, not shown, and is capable of withstanding temperatures of more than. -200 .C.,;forexample mineral oil, Dowotherm, or the" like: The temperature. of.-the fluid.must..be.maintained below-the melting pointnoflth'e polymer from which .the ,yarn is made. A

pump .13.. delivers the -hot 'f.liquid..through ..the ..;duct 211a .into .the interiorofthe .hollow;casing;,11, whenceit==re- .turns .throughthe.ductI1b.-

'Eircessive .heat 1 loss is .prevented-v -by; a; reflecting-vin- .sulatedQcove plate-11cwhich. is.di sp osedonttthe zsidecof the .casing..11 .over whichntheyarn. 8 passesor reflects heat from "the .casing onto the yarn..

The'bo'iler'll may supply hot-liquid .to.a..pluralit y,.of casings 1'1"which may constitute abay or 'side of 'aIframe thereby insuring complete uniformity of temperature .ap-

"plied to'all'yarnsof the frame.

From-the eyelet 1"0' the'yarnspasses into a false twister 14 of standard construction which is shown as driven by a belt from the main driving shaft A. The twister 14 includes a rotary member which causes rotation of the yarn passing therethrough and thereby imparts a false twist which travels downwardly along the yarn counter to the direction of feed and produces a twist in the portion of the yarn in contact with the heated casing 11. The temperature of the casing 11 is controlled to heat the yarn in contact therewith to a temperature suited to set the twist in the yarn so that as the yarn p'asses upwardly beyond the false twister 14 and is again untwisted, the curl produced by the set twist remains in the individual filaments.

From the false twister 14 the yarn 18 passes to a winding bobbin 16 which is driven by contact with a driven roller 15. The roller 15 is driven from the main shaft A through bevel gears Band B and a gear train comprising gears 17, 18, 19 and 20. The bobbin 16 is mounted on a pivoted bracket 23 so that the winding rests on the driving roll 15 and is driven thereby to wind the yarn at a constant peripheral speed. A traversing guide 21 guides the yarn 8 onto the bobbin 16.

Transmission ratios between the shaft A and the rollers 3 and 15 are so selected as to permit any desired shrinkage to take place in the yarn 8 between the two sets of rolls. Since the various rolls of a given frame may be driven from the same shafts the shrinkage will be maintained the same for all of the yarn treating stations of the frame. The shrinkage in length is normally because of the twist which is imparted to the yarn by the false twister and the ratio of the rolls 3 and 15 is selected in accordance with the desired characteristics of the product.

The above described mechanism produces a high curl in yarns from various thermoplastic materials, such as polyhexamethylene adiparnide or polyacrylonitrile, or other materials having thermoplastic properties. Since the curl is set by dry heat due to the contact with the outside of a heated plate 11 it is completely stable.

A further embodiment of the invention is shown in Fig. 3 in which the various parts which correspond to the parts of Figs. 1 and 2 have been omitted. In Fig. 3 the apparatus is the same as in Figs. 1 and 2 except that the heated casing 11 is replaced by a pair of electrodes F between which the yarn passes in its travel from between the guide roll 10 and the false twister 14. A source G of very high frequency current is connected to the electrodes F so that a high frequency electrostatic field is produced which is adapted to heat the yarn to the temperature necessary for setting as it passes the electrodes. The treatment is otherwise similar to that described in connection with Figs. 1 and 2.

In Fig. 4 the apparatus is assumed to be identical wi that in Figs. 1 and 2 except that the heated casing 11 of Figs. 1 and 2 is replaced by a bank of infra red heat sources 22 which are disposed to apply infra red heat ontQ the yarn 8 as it passes from the roll 10 to the false twister.

' a person skilled in the art.

What is claimed is:

An apparatus for producing a curled yarn from a bundle of synthetic thermoplastic filaments comprising a false twister, feed rolls for feeding yarn to said false twister, a bobbin on which the yarn is wound after passing through said false twister, means driving said feed j rolls and said bobbin at a predetermined speed ratio for maintaining a constant predetermined shrinkage in said bundle, a pair of electrodes disposed between said feed rolls and said false twister on opposite sides of the bundle thereby applying dry heat to the bundle suited to heat the bundle to a temperature to set the curl therein.

References Cited in 4 the file of this patent UNITED STATES PATENTS Story Mar. 22, Vandamme et al. Sept. 4, Klein Jan. 15,

FOREIGN PATENTS Germany June 18, Great Britain May 26, Austria June 19, Belgium June 19, Brazil -2 Sept. 30, Canada June 18, Denmark June 18, Spain June 19, Holland June 18, Italy June 4, Sweden June 19,

Switzerland June 18, 

